This is a very good quality print (scan) of the original SONY service manual. The original from Sony is on very thin paper. Nevertheless it is very clear and sharp and excellent readable. I'm very satisfied to have now this rare document. I've looking for it many years (infrequent). It contains very detailed circuit diagrams, exploded views, part lists, PCB view with good readable connection lines. Very recommended.
3-3. N1~N4 PADS
Never solder or desolder these pads, because they have been selected best in the production line. A new PCB ass'y as a spare parts will be supplied with factory adjustment of these pads.